How to send mail without login with Gmail API?

Question

Good work everyone, Gmail API also requires user approval. But I have no idea how to use the token. I have to send a control mail to the user. Can I do without tokens? I am making request with HttpClient. I am not using credentials.json. As a postman, I can take and take tokens, but the token must not be renewed. Sorry for my English. Thanks

I tried sending mail with Smtp Server. But it is blocked for security reasons. The only healthy solution is to send mail via Gmail API.

Answer 1

Using SMTP:

public class EmailService
{
    public Task Execute(string UserEmail, string Body, string Subject)
    {
        //enable less secure apps in account google with link
        //https://myaccount.google.com/lesssecureapps
        try
        {


            SmtpClient client = new SmtpClient();
            client.Port = 587;
            client.Host = "smtp.gmail.com";
            client.EnableSsl = true;
            client.Timeout = 1000000;
            client.DeliveryMethod = SmtpDeliveryMethod.Network;
            client.UseDefaultCredentials = false;
            client.Credentials = new NetworkCredential("***email here****", "****password here****");
            MailMessage message = new MailMessage("***email here****", UserEmail, Subject, Body);
            message.IsBodyHtml = true;
            message.BodyEncoding = UTF8Encoding.UTF8;
            message.DeliveryNotificationOptions = DeliveryNotificationOptions.OnSuccess;
            client.Send(message);
            return Task.CompletedTask;
        }
        catch (Exception e)
        {
            Console.Error.Write(e);
            return Task.CompletedTask;
        }
    }
}

Also as mentioned in comment, enable less secure apps in google account. https://myaccount.google.com/lesssecureapps

hint: less secure can't be enabled for emails with 2-step verification.